Linux系统中su和sudo命令的用法
在Linux系统中，用户可以通过su和sudo命令来实现权限管理，su(Switch User)命令用于切换用户，而sudo(Super User Do)命令则允许普通用户以超级用户(root)的身份执行命令，本文将详细介绍这两个命令的用法及相关知识。
su命令的用法
1、切换到root用户
su命令的基本用法是切换到root用户，在终端输入以下命令：
su
然后按回车键，系统会提示输入root用户的密码，输入正确的密码后，即可切换到root用户。
2、以其他用户身份登录
su命令还可以用来以其他用户身份登录，假设要切换到用户testuser,可以输入以下命令：
su testuser
系统会提示输入testuser用户的密码，输入正确的密码后，即可切换到testuser用户。
3、使用-c选项指定要执行的命令
su命令还支持使用-c选项指定要执行的命令，要在root用户下执行ls命令，可以输入以下命令：
su -c "ls"
系统会提示输入root用户的密码，输入正确的密码后，即可在root用户下执行ls命令。
sudo命令的用法
1、以普通用户身份执行特定命令
sudo命令的基本用法是以普通用户身份执行特定命令，在终端输入以下命令：
sudo command_name
command_name是要执行的命令名称，系统会提示输入当前用户的密码，输入正确的密码后，即可以普通用户身份执行指定的命令，需要注意的是，并非所有的命令都支持使用sudo命令，具体需要根据实际情况判断。
2、以root用户身份执行任意命令
sudo命令还支持以root用户身份执行任意命令，在终端输入以下命令：
sudo -i
系统会提示输入当前用户的密码，输入正确的密码后，即可以root用户身份登录，然后可以执行任意需要root权限的命令，同样，需要注意的是，并非所有的命令都支持使用sudo -i命令，具体需要根据实际情况判断。
相关问题与解答
1、sudo和su有什么区别？
答：sudo和su的主要区别在于权限管理，su命令用于切换用户，只能切换到指定的用户；而sudo命令允许普通用户以超级用户(root)的身份执行命令，从而实现对系统资源的管理，在使用过程中，应根据实际需求选择合适的命令。
2、如何为某个用户配置sudo权限？
答：为某个用户配置sudo权限，需要编辑/etc/sudoers文件，在终端输入以下命令：
visudo
打开文件后，找到类似以下内容的行：
User privilege specification root ALL=(ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL All root privileges and all on *.* for everyone else = root (ALL:ALL) ALL End of file Defaults are permissive, in this case we will deny everything %admin ALL=(NONE) NOPASSWD: ALL Allow members of group admin to run any command without a password %wheel ALL=(ANYONE|ROOT) NOPASSWD: ALL Allow members of wheel group to run any command without a password %admin ALL=(ANYONE|ROOT|wheel) NOPASSWD: ALL Allow members of admin group to run any command without a password %users ALL=(ANYONE|ROOT|wheel) NOPASSWD: ALL Allow members of users group to run any command without a password %public ALL=(ANYONE|ROOT|wheel|users) NOPASSWD: ALL Allow anyone to read the contents of /etc/passwd %wheel ALL=(ANYONE|ROOT|wheel|users|public) NOPASSWD: /etc/passwd Allow members of wheel group to read the contents of /etc/passwd %admin ALL=(ANYONE|ROOT|wheel|users|public) NOPASSWD: /etc/passwd Allow members of admin group to read the contents of /etc/passwd %users ALL=(ANYONE|ROOT|wheel|users|public) NOPASSWD: /etc/passwd Allow members of users group to read the contents of /etc/passwd %public ALL=(ANYONE|ROOT|wheel|users|public) NOPASSWD: /etc/passwd Allow anyone to read the contents of /etc/shadow %wheel ALL=(ANYONE|ROOT|wheel|users|public) NOPASSWD: /etc/shadow Allow members of wheel group to read the contents of /etc/shadow %admin ALL=(ANYONE|ROOT|wheel|users|public) NOPASSWD: /etc/shadow Allow members of admin group to read the contents of /etc/shadow %users ALL=(ANYONE|ROOT|wheel|users|public) NOPASSWD: /etc/shadow Allow members of users group to read the contents of /etc/shadow %public ALL=(ANYONE|ROOT|wheel|users|public) NOPASSWD: /etc/shadow Allow anyone to read the contents of /etc/group %wheel ALL=(ANYONE|ROOT|wheel|users|public) NOPASSWD: /etc/group Allow members of wheel group to read the contents of /etc/group %admin ALL=(ANYONE|ROOT|wheel|users|public)
原创文章，作者：K-seo，如若转载，请注明出处：https://www.kdun.cn/ask/189025.html
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